Detection and molecular characterization of African swine fever virus recovered from Ornithodoros ticks of the Serengeti Ecosystem, Tanzania.

African swine fever (ASF) is a highly lethal hemorrhagic disease of domestic pigs and Eurasian wild boars, caused by ASF virus (ASFV). In Africa, ASFV is maintained in a sylvatic cycle involving wild suids, primarily warthogs (Phacocherus africanus) and Ornithodoros ticks. Despite ASF outbreaks in Tanzania, the role of the sylvatic cycle in areas with high wildlife-livestock interactions remains understudied. This study aimed to detect and characterize ASFV in Ornithodoros ticks from warthog burrows in the Serengeti ecosystem. Soft ticks were collected from warthog burrows and screened for ASFV using quantitative polymerase chain reaction (qPCR). A total of 1,003 Ornithodoros ticks were collected from 25 burrows and qPCR detected ASFV in ticks from 9 burrows. Conventional PCR targeting the ASFV B646L (p72) gene, intergenic region (IGR) between I73R and I329L genes, and the central variable region (CVR) of the B602L gene was conducted in positive samples. The amplicons were sequenced and used for phylogenetic analysis. Phylogenetic analysis of the nucleotide sequences of B646L (p72) gene showed that the identified ASFV strains clustered within genotype X, which has been previously associated with outbreaks in domestic pigs in Tanzania and neighboring countries. Analysis of the IGR and the CVR of the B602L gene confirmed the high genetic similarity between the detected strains and those linked to previous ASF outbreaks in Tanzania and neighboring countries. The findings of this study highlight the need to prevent virus spillover from the sylvatic cycle for efficient control of the ASF in Tanzania.